Freestanding and Permselective Graphene Oxide Membranes Assembled at Liquid/Liquid Interface through Novel "Stitch Chemistry"

题目：用化学方法将氧化石墨烯纳米片拼接到分离膜中是化工、石化和生物工程等行业急需的低能耗净水技术。此外，传统的聚合物和陶瓷基膜技术在生物燃料分离方面面临重大挑战。氧化石墨烯（GO，一种厚度小于1.0 nm的片状材料）作为一种膜材料在水分离方面具有很大的潜力。这种膜将由多层这种片状材料组成。提出的研究将使用新的“缝线”分子作为工具，将氧化石墨烯片组装成具有所需微观结构模式和层间距的膜。这些膜的设计是为了在广泛的分离实践中实现水的超选择性分离。这项研究的结果是提供一种可转移的独立膜处理技术，能够彻底改变生物燃料的分离效率，并大大提高水的净化能力。通过对研究生的专业培训、研究生课程的开发、促进STEM教育和对大学预科学生的重点外展活动的参与，解决了教育的广泛影响。本研究的重点是对界面传输、反应动力学和氧化石墨烯片成独立膜的自组装现象的基本理解，利用液体/液体界面促进聚合化学。通过使用新颖的拼接分子来影响氧化石墨烯膜的层间距、膜表面的形成以及孔通道的表面化学性质，可以实现液/液界面的自组装。该研究将使用生物燃料分离和水净化应用的例子来测试所得膜的选择性和渗透性。具体的研究目标是：1)了解氧化石墨烯薄片在液/液界面上进入膜的输运行为和组装现象；2)利用氧化石墨烯基面上的反应基团调节氧化石墨烯膜孔微观结构和表面化学性质，影响膜的结构和化学功能；3)揭示了氧化石墨烯膜在生物燃料超选择性分离和水净化应用中的工艺-结构-性能关系。这项技术的可转让性将使其能够立即推广到广泛的分离应用领域。

Proposal Number: 1603264, PI: Zhu, JiahuaTitle: Chemically Stitching Graphene Oxide Nanosheets into Separation Membranes Purifying water from processing streams with low energy consumption is urgently needed in the chemical, petrochemical and bioengineering industries. In addition, conventional polymer- and ceramic-based membrane technologies have significant challenges in biofuel separations. Graphene oxide (GO, a sheet material with a thickness less than 1.0 nm) has been explored as a membrane material with great potential in water separations. The membrane would consist of layers of this sheet material. The proposed research will use novel "stitch" molecules as a tool to assemble GO sheets into a membrane with desired microstructure pattern and layer spacing. These membranes are designed to achieve permselective separation of water in a broad range of separation practices. The outcome of this research is to offer a transferrable freestanding membrane processing technology that is capable to revolutionize biofuel separation efficiency, and greatly improve water purification capability. The educational broader impacts are addressed through professional training of graduate students, development of graduate curriculum and promoted STEM education and engagement in focused outreach activities to pre-college students. This research focuses on the fundamental understanding of interfacial transport, reaction kinetics, and self-assembly phenomena of graphene oxide sheets into freestanding membranes at using polymerization chemistry facilitated by a liquid/liquid interface. The self assembly at the liquid/liquid interface will be enabled with the use of novel stitching molecules to impact the layer to layer spacing of the GO membrane, the formation of the membrane surface, and the surface chemistry of the pore channels. The research will use examples of biofuel separation and water purification applications to test the selectivity and permeability of the resultant membranes. The specific research goals are to: 1) understand the transport behavior and assembly phenomena of GO sheets into membranes at the liquid/liquid interface; 2) tune GO membrane pore microstructure and surface chemistry properties using reactive groups in the GO basal planes to impact the membrane's structure and chemical function; and 3) reveal the process-structure-property relationships of GO membranes targeting permselective biofuel separation and water purification applications. The transferability of this technology will enable its immediate dissemination to a wide range of separation applications.